Modern cameras have an increasing number of features requiring more interaction with the user, such as setting time and date, flash operation, and exposure controls. To facilitate interactions with the users, these cameras incorporate a display, such as a liquid crystal display (LCD) screen. Many manufacturers use a combination of buttons, switches, and dials for the user interface. A camera with a reconfigurable mechanical button is described in U.S. Pat. No. 5,408,287.
The main camera function is that of the shutter release button. Desirable features for this function include intuitive location so the user can find it by touch, low force operation, low component cost, and a two position activation feature, where the first position causes the camera to perform calculations for focus range detection, exposure calculation, automatic flash activation, and user notification of parameters such as low light level that may affect image quality. The second position, which is reached after passing through the first position, activates the shutter. U.S. Pat. No. 4,247,188 is an example of the prior art using this two position activation. This allows the user to frame and "lock" settings related to the current image, and in the case of user notification functions, such as a warning light, the user can elect to not take the picture and take corrective action.
FIG. 1 shows a user interface according to the prior art, with camera 10, a conventional display screen 12, shutter release button 14, and user interface buttons 16 and 18. One of the problems with the current art is the increasing number of functions require more buttons and complex menu schemes to provide the interface functions with the fewest number of buttons. Additionally, the location of the shutter button 14 on camera 10 as shown in FIG. 1 can cause camera shake, especially if the button is "punched". It is well known in the art to use an electronic shutter release to reduce the force required for shutter activation, as described in U.S. Pat. No. 4,199,245. However, placing an electronic shutter release at the same location as a mechanical shutter release encourages using the same force level.
In another example of the current art, the Nikon Coolpix 300 digital camera uses a touch screen display as the user interface. It has a conventional two position shutter release button, as well as a triggered shutter activation from touching a permanent icon adjacent to the display screen. However, this second shutter release does not have a two position activation, so there is no means to use the partial activation as described earlier
Another example of using touch screens with cameras (specifically electronic cameras) are described in U.S. Pat. No. 4,827,347. The display is used to select images from a plurality of displayed images.
It would be desirable then, to provide a camera with many controls for controlling different camera functions, and yet which controls permit a user to readily find and use such controls. It would further be desirable in the case of a shutter control, if a two position shutter function could be preserved but with a reduction in the tendency of a user to "punch" the control with consequent camera vibration during picture taking.